Quarter	Percent
1968-01-01	82.1216572618376
1968-04-01	84.6850160067532
1968-07-01	84.5931221376510
1968-10-01	83.9921536251301
1969-01-01	82.2128707590120
1969-04-01	84.5595187987450
1969-07-01	84.4467611702981
1969-10-01	83.7861019751404
1970-01-01	82.6565540051362
1970-04-01	84.5742990030386
1970-07-01	84.3399623119096
1970-10-01	83.7693866292664
1971-01-01	83.5080686290833
1971-04-01	85.2467557441402
1971-07-01	84.5859563103713
1971-10-01	84.1478203809199
1972-01-01	83.2816933268086
1972-04-01	85.0340706058530
1972-07-01	84.8221281517856
1972-10-01	84.0952232780660
1973-01-01	83.5329559072277
1973-04-01	85.1386460785522
1973-07-01	85.2085595514516
1973-10-01	84.6424053376493
1974-01-01	83.6718485877919
1974-04-01	85.1454070197931
1974-07-01	84.6580830367598
1974-10-01	84.2593173562924
1975-01-01	82.7056289960852
1975-04-01	84.0130260898799
1975-07-01	83.9929525739129
1975-10-01	84.0179212068655
1976-01-01	82.7918446385674
1976-04-01	83.7708761244706
1976-07-01	83.8534376755047
1976-10-01	83.5018218067600
1977-01-01	82.3908400368801
1977-04-01	83.4377722452436
1977-07-01	83.4231453507360
1977-10-01	83.1034130837712
1978-01-01	82.1402337429649
1978-04-01	83.6810332495309
1978-07-01	82.9966730612448
1978-10-01	82.7381232908579
1979-01-01	81.9518640196047
1979-04-01	83.7794111811550
1979-07-01	83.4958905985164
1979-10-01	83.0751517460114
1980-01-01	82.1417863385148
1980-04-01	83.4679995712308
1980-07-01	83.2892085887419
1980-10-01	82.8637174372487
1981-01-01	82.3709175321768
1981-04-01	83.4271942989119
1981-07-01	83.1303116083914
1981-10-01	82.4390610171002
1982-01-01	82.0056406666654
1982-04-01	83.3802987966344
1982-07-01	82.8704099397917
1982-10-01	82.6185645573764
1983-01-01	81.7952843631980
1983-04-01	83.1694925773521
1983-07-01	82.7726726445090
1983-10-01	82.2902230409373
1984-01-01	81.4497038878798
1984-04-01	82.5468972567022
1984-07-01	82.3239349076137
1984-10-01	81.9830117573604
1985-01-01	81.0001804812786
1985-04-01	82.2134474138407
1985-07-01	81.8572253371953
1985-10-01	81.2357752162558
1986-01-01	80.5626951305781
1986-04-01	81.7037684747976
1986-07-01	81.6304424831834
1986-10-01	80.9216819501589
1987-01-01	79.9578544369106
1987-04-01	81.0730272903829
1987-07-01	81.3249978074214
1987-10-01	80.7696536141724
1988-01-01	79.8539195458209
1988-04-01	81.4241754864726
1988-07-01	81.2260746136153
1988-10-01	80.9111033379124
1989-01-01	80.1838632872674
1989-04-01	81.5619557483980
1989-07-01	81.4011648646589
1989-10-01	81.1818000875874
1990-01-01	80.5064643071817
1990-04-01	81.9513450743088
1990-07-01	81.7746697638462
1990-10-01	81.8504796143722
1991-01-01	81.0987798686597
1991-04-01	82.4363281315169
1991-07-01	82.2179662047956
1991-10-01	82.2794447971722
1992-01-01	81.8173902735758
1992-04-01	82.6035921400678
1992-07-01	82.5193337018854
1992-10-01	82.5803261636634
1993-01-01	81.7379435240696
1993-04-01	82.7022641195844
1993-07-01	82.6370915556044
1993-10-01	82.4371288549561
1994-01-01	81.2854043122426
1994-04-01	82.3892457805875
1994-07-01	82.3498976623853
1994-10-01	81.9807333865187
1995-01-01	81.0320777553380
1995-04-01	82.1552922014595
1995-07-01	82.3993192929081
1995-10-01	82.0063833325636
1996-01-01	81.2630223268354
1996-04-01	82.3420586326748
1996-07-01	82.7082716649673
1996-10-01	82.4060858600339
1997-01-01	82.0446031123504
1997-04-01	83.0657578076136
1997-07-01	82.6838627645628
1997-10-01	82.2621329609056
1998-01-01	81.4468821467258
1998-04-01	82.0539621632649
1998-07-01	81.8306951135582
1998-10-01	81.6574720111908
1999-01-01	80.8259131633122
1999-04-01	81.1631499293070
1999-07-01	81.3985174396712
1999-10-01	81.3261819186158
2000-01-01	80.3622024130628
2000-04-01	81.2542747513128
2000-07-01	81.3148904413537
2000-10-01	81.3470674066602
2001-01-01	80.4360829974786
2001-04-01	80.9453742096228
2001-07-01	80.7683406618838
2001-10-01	80.0554945333600
2002-01-01	79.6100273202160
2002-04-01	80.0806656519846
2002-07-01	80.1877469746203
2002-10-01	79.9253402294562
2003-01-01	79.4239238213060
2003-04-01	79.8815794684596
2003-07-01	80.2009313277611
2003-10-01	80.3024283328390
2004-01-01	79.4127932796257
2004-04-01	80.2296511184097
2004-07-01	80.2720912544329
2004-10-01	80.4524790475551
2005-01-01	79.6389462654160
2005-04-01	80.5546497987115
2005-07-01	80.9924078333798
2005-10-01	80.8424569712397
2006-01-01	80.3912637756324
2006-04-01	81.4682830571390
2006-07-01	81.2974826822508
2006-10-01	81.1742274892849
2007-01-01	81.1547226498063
2007-04-01	82.3327915111894
2007-07-01	82.0477924641987
2007-10-01	81.8072851347407
2008-01-01	81.1915972383670
2008-04-01	82.1531011915298
2008-07-01	81.8656567393030
2008-10-01	81.6499861307258
2009-01-01	80.5477608197524
2009-04-01	80.5294944853133
2009-07-01	80.0970567300236
2009-10-01	80.1229086331242
2010-01-01	79.8912722382544
2010-04-01	80.4012164035527
2010-07-01	80.3004280285162
2010-10-01	80.2403913280925
2011-01-01	80.1909436630905
2011-04-01	81.1691638950971
2011-07-01	80.5632772170841
2011-10-01	80.4028805237859
2012-01-01	79.8900888822615
2012-04-01	80.5143541135805
2012-07-01	80.5009173718554
2012-10-01	80.5864615403211
2013-01-01	80.0828719377375
2013-04-01	81.1068853168661
2013-07-01	81.0526722882719
2013-10-01	81.1574333783301
2014-01-01	81.1734285992234
2014-04-01	81.9640081508177
2014-07-01	81.8183224698136
2014-10-01	81.6175900298834
2015-01-01	81.5185214539296
2015-04-01	81.9696025997597
2015-07-01	82.0445551138960
2015-10-01	82.1920675399528
2016-01-01	81.9731263415534
2016-04-01	82.7975595300016
2016-07-01	82.8025225952281
2016-10-01	82.8392842552482
2017-01-01	82.4486402914594
2017-04-01	83.1511516129959
2017-07-01	83.1466542705960
2017-10-01	83.2651918235768
2018-01-01	83.3304148052793
2018-04-01	84.2426331363171
2018-07-01	83.9828897299496